Corrosion inhibition and anti-bacterial efficacy of benzalkonium chloride in artificial CO2-saturated oilfield produced water

Corrosion inhibition by benzalkonium chloride (BKC) against anaerobic CO2 corrosion and microbiologically influenced corrosion was studied using surface analysis, weight loss and electrochemical measurements. Results showed that the minimal bactericidal concentration of BKC against Desulfotomaculum nigrificans (D. nigrificans) was 40 mg L−1. While at this concentration the planktonic D. nigrificans cell count could recover after 21-day incubation, it resulted in 4 log reduction in sessile D. nigrificans cell count. When 80 mg L−1 BKC was used, both planktonic and sessile D. nigrificans became undetectable. It was found that at these concentrations, BKC reduced both uniform corrosion and pitting corrosion.